1. Field of the Invention:
The present invention relates to coin discriminating apparatus and method capable of electrically discriminating whether a used coin in vending machines etc. is genuine or not and also detecting its denomination.
2. Description of the Prior Art:
Recently, vending machines become very popular. And these vending machines are normally equipped with coin discriminating apparatus, which are normally required high performance enough to be capable of discriminating coins.
Conventional coin discriminating apparatus comprises three different kinds of sensors for detecting material, thickness, and outer-diameter, respectively, and signal processing circuits receiving output signals from these sensors. With this arrangement, genuine or not of the coin to be detected is discriminated by detecting all of material, thickness, and outer-diameter of the coin.
As relevant prior arts relating to this kind of technique, there have been known the U.S. Pat. No. 3,870,137 and the U.S. Pat. No. 3,918,565.
However, in such a conventional constitution, there was a problem such that an unauthorized use or unfair use of counterfeit coins such as a flat metal made of a similar material and having similar thickness and outer-diameter might be undetected or missed. Furthermore, in view of number of sensors, it requires at least three sensors for all the detection of material, thickness, and outer-diameter of the coin to be detected.